Information processing apparatus having a multitasking function with one or more optical discs

ABSTRACT

A high-performance optical information processing apparatus having various hardware for arriving at multitasking function. The optical information processing apparatus provides disc-loading and -unloading flexibility, allows a user to launch a software program or simultaneously several software programs directly from an optical disc and/or several optical discs stored therein, eliminates tedious and time-consuming software installation, affords a kind of copyright protection to software, and alleviates the burden of accessing a hard-disk drive during the process of information reproduction.

FIELD OF THE INVENTION

The present invention relates generally to the field of informationprocessing utilizing optical discs and particularly to a high-efficientoptical-disc-type apparatus that allows a host computer to effectivelyand/or multitaskingly perform various information processing actionsdirectly from optical discs so as to alleviate the heavy burden of ahard-disk drive in the process of information reproducing.

BACKGROUND OF THE INVENTION

An optical disc or compact disc (CD) is made from a transparent plasticmaterial with a thickness of about 1.2 mm that contains a protected thinmetal film wherein pits (or depressions) are formed. The pits have lightreflectivities different from the light reflectivity of nonpittedportions of the metal film, thus forming a series of 0s and 1s fordigital storage of data. In production, a master disc is first developedfrom a glass disc coated with a uniform layer of photoresist materialthat is subjected to a series of exposures to a high-power energy beamor laser for forming various pits via the technology ofphotolithography. The master disc is then used to develop a nickelmother for use in stamping out multiple copies of the discs intransparent plastic material. Each of these is then coated with a thinmetallic reflecting layer and then with a protective polymer coating ontop of that. When reproducing the stored information, a low-power laseris used to sense the presence or absence of pits. Because a laser beamcan be so focused, adjacent tracks of the spiral of pits need be nolarger than 1.6 μm. As a result, one side of a typical 120-mm (4.72-in)CD can have 20,000 tracks for holding a minimum of 500 megabytes of datawhich can easily store the text of a 20-volume encyclopedia, while bothsurfaces of a typical 133-mm (5.25-in) or a 89-mm (3.5-in) floppy diskare able to respectively hold only 1.2 or 1.44 megabytes.

Owing to the nature of their high storage capacity, optical discs areespecially suitable for storing information requiring or taking largestorage spaces, such as patent information, video data, and digitalaudio files. In addition to the floppy-disk version, software developershave recently produced the 120-mm read-only-memory CD (CD-ROM) versionof executable software programs, such as IBM® OS/2 and MicrosoftWindows® 95 for use in personal information processing apparatuses, suchas desktop- or notebook-type computers.

Even though becoming increasingly popularly equipped in computers, aCD-ROM drive plays a much less significant role in informationprocessing when compared with a hard-disk drive that utilizes themagnetic recording technology. This is because the currently availablecomputers are designed to execute a program or software basicallythrough reproducing the information stored on hard-disk drives,especially when the size of a program exceeds the storage capacity of afloppy disk. When sold to an end user, a software program for use inapplications such as disk controlling, word processing, spread sheet,drawing, and presentation making, is compressedly stored on a pluralityof floppy disks or an optical disc. Regardless of being either stored infloppy disks or an optical disc, a purchased software program needs togo through a tedious software installation process through which allprogram files are decompressedly copied to a hard-disk drive wherefromthe software program is then executed. In accordance with thisconventional practice, the storage space of a hard-disk drive is quicklyfilled up. This not only incurs indirect cost in the expenditure of thehard-disk drive in addition to the price of the purchased softwareprogram to the end user, but eventually slows down the read-and-writeoperation efficiency of the hard-disk drive because any data filescreated are constantly rewritten, fragmentally relocated, and eventuallyscattered all over the hard-disk drive. Accordingly, a longer time isneeded to find all of the data of a particular file. The only remedycurrently available for this problem is to routinely run a hard-diskmaintenance process in order to remove file fragmentation.Unfortunately, as more software programs or data files are stored on thehard-disk drive, the hard-disk maintenance process becomes more and moretime-consuming, because it also involves relocation of the program filesthat occupy most of the space of the hard-disk drive but are neverchanged or altered throughout the entire life of their usage. Stillthere is another concern that a hard-disk drive is subject tononphysical damages, for instance, such as program files being truncatedor cross-linked due to improper assessing or writing during informationreproducing or being infected by computer virus. As a result, a softwareprogram becomes corrupted; and, another tedious software installationprocess is again needed. All of these point to the fact that thecurrently available computers are designed to perform informationprocessing by reproducing the information stored on hard-disk drives,and, this is not necessarily desirable.

Since a software program is mostly stored on a plurality of floppy disksfor its distribution, an end user is routinely advised to make a set ofbackup copies because floppy disks are susceptible to physical andexternal damages. Inevitably another disadvantage is incurred: atime-consuming process for making backup copies.

The need to install a purchased software program to a hard-disk drivefurther incurs another problem: it is extremely difficult for softwaredevelopers to stop or prevent illegal-copying of software. There areexisting hardware-type protection devices and password-type protectionapproaches but they are affordable only for high-price software programswith an aim of selling at most a few thousand copies for use in tradingstocks or futures in real time, for instance. In contrast, volumesoftware programs are sold in sealed envelopes. Once a sealed envelopeis opened, an end user is assumed to accept the software licenseagreement set by a software developer and, the software program is notreturnable. Unfortunately, there is no practical way to prevent an enduser from illegally coping such a software program. As the softwaredevelopers producing high-volume and low-price software programs sufferfrom their products being illegally copied, the consumers lose theiropportunity to try out a software program before purchasing.

In view of the disadvantages and problems mentioned hereinbefore, it isclear that currently available computers and optical disc or floppy-diskapparatuses are not designed to achieve their optimal potential. Owingto the nature of durability and storage capacity far superior to that ofa floppy disk, an optical disc has a greater potential to become amemory storage medium for constructing a special type of apparatus toremedy the disadvantages currently encountered in the availableinformation processing apparatuses. Thus, main interest of the presentinvention is to design a high-efficient optical disc apparatus wherefromsoftware programs can be directly launched so as to eliminate thetedious, time-consuming software installation and thus to offer analternative of copy-right protection to software developers, as well asto alleviate the heavy burden of a hard-disk drive in informationprocessing. Also essential for an information processing apparatus ofthis type is the feature of disc-loading and -unloading flexibility thatallows a user to easily change or replace desired discs at will. Inorder to achieve the highest efficiency in information reproduction, anydisc and disc positions should be readily accessible by at least oneoptical unit at any time. An optical read head should be able to travelfrom one disc to another, and its travelling should be limited toone-directional movement (either linear or circular) becausemultiple-directional or three-dimensional movement greatly slows downoptical-read-head travelling efficiency. It is also highly desirablethat an information processing apparatus of this type in accordance withthe present invention comprises multiple disc sites each able todetachably hold a disc so that various software programs are readilyavailable because Microsoft®, WordPerfect®, or Lotus® are most likely toproduce their own software discs.

Multitasking or multiprocessing is another highly desirable feature foran information processing apparatus of this type in accordance with thepresent invention. In the context of the present invention, multitaskingor multiprocessing is defined as referring to separate hardware controlunits that allow execution of separate or several software programssimultaneously. Due to containing a plurality of discs wherefrom severalprograms can be directly launched, an information processing apparatusof this type needs a safeguard device to prevent the discs storedtherein from being unauthorizedly removed. Further, this type ofinformation processing apparatus should be compact enough to beinternally installed in a computer, because with the trend towardsminiaturization, no future computers would be spacious enough forinternally storing a bulky CD apparatus holding more than twohorizontally spaced 120-mm discs.

An information processing apparatus of this type with all or a selectedcombination of the features mentioned hereinbefore is not yet readilytaught by the prior arts. This is discussed as follows.

U.S. Pat. No. 4,644,515 describes a laser-disc digital data videostorage system in which multiple discs stacked upon a common rotatabledrive shaft are to be read by a plurality of stationary read head arraysfor commercial use. This jukebox-like system allows multiple users toaccess its information by employing a huge number of read heads, forexample 55,000 heads (or one head for each track), in each read headarray. One of the main disadvantages of this type of system is itslacking disc-loading and -unloading flexibility; that is, a user cannotaccess the common drive shaft for changing or replacing a desired discat will. U.S. Pat. No. 4,888,751 describes an image informationprocessing system in which (at least) an optical unit having an opticalhead arm rotatable through 180 degrees is used to scan the informationstored on either adjacent side of multiple discs that are stacked atpredetermined intervals on a detachable mounting mechanism. Thedetachable mounting mechanism provides some improvement in disc-loadingand disc-unloading flexibility over U.S. Pat. No. 4,644,515 mentionedabove, but is still inconvenient for a user to replace or change adesired disc at will due to the stacking nature of its disc arrangement.This prior apparatus is afforded with a plurality of optical units suchthat one of the optical units is most likely readily available forvertically moving to a next selected disc. In such a manner, the processof accessing information recorded on a different disc is speeded up;otherwise, the access time will be unacceptably slow since an opticalunit in such a system has first to retract out of a disc space byswinging, to move vertically to a new disc space to be entered, and thento seek a new track by swinging. In this prior art, it is obvious thatthe presence of the multiple optical units is intended for speeding updisc-track access time between discs, but not for achieving anymultitasking.

To improve the access time for reproducing the information stored ondifferent discs, U.S. Pat. No. 5,189,652 describes a stationary-typeoptical disc apparatus that is characterized by a plurality of opticalunits each slidable into a disc space to access a predetermined positionof a disc. Although it reduces the access time, this system neitheraffords disc-loading and -unloading flexibility referred to abovebecause of its stationary and disc-stacking natures, nor provides anymultitasking capability.

Instead of using the approach of stacking as used in the abovementionedprior arts, U.S. Pat. No. 4,722,078 employs a plurality of horizontallyspaced disc compartments (or trays) each holding an audio disc which,upon selection can be scanned by a disc playback module that is capableof being horizontally transported between the disc compartments. Becauseeach disc compartment has a separate means for independently extendingand retracting out of and into the apparatus, this audio CD playerrequires multiple front entrances. In other words, this configuration istoo bulky and cannot be internally installed into the existing drivebays of current computers, which typically have dimensions of 146-mm(5.75-in) in width, 41-mm (1.75-in) in height, and up to about 254-mm(10-in) in depth. In addition, it lacks multitasking capability.

Other examples using the nonstacking approach are embodied in U.S. Pat.Nos. 5,146,451, 5,193,079, and 5,251,192. However, in accordance withthese prior arts, discs are not readily accessible at any time becausetheir disc-storage sites need to move to a predetermined position beforea selected disc becomes accessible, thus slowing downinformation-reproduction efficiency. Similar inefficiency is also seenin U.S. Pat. Nos. 5,119,354 and 5,335,218 that utilize a disc transfermeans comprising a drive roller to deliver a disc selected from a disccontainer or magazine (having a plurality of discs in a pile therein) toa disc drive for rotating and thus reading. Although improvingdisc-loading and -unloading flexibility referred to above, all of theseprior apparatuses with capability of holding a plurality of discsrequire several additional transitional stages before a selected discbecomes accessible to a singular optical unit. These apparatuses arebest for use in as-intended audio applications, not for use ininformation processing that requires high-efficient, high-speedinformation reproduction.

Providing disc-loading and -unloading flexibility to some extent, U.S.Pat. No. 5,043,963 provides an information processing apparatus capableof playing a disc selected from a plurality of sizes such as 80-, 120-,200- or 300-mm in diameter. These multisized discs are laid on a traywherein a circular-like section used to store a plurality of small-sizeddiscs is rotatable for their selection. Different versions ofapparatuses capable of playing optical discs with different diametersare seen in U.S. Pat. Nos. 5,119,354 and 5,253,235. The ability ofplaying the discs with different diameters is desirable, however, thediscs in these prior apparatuses fail to be readily accessible by theirsingle optical unit at any time.

In the conventional CD apparatuses, a single clamp device (or pressmember) capable of pivoting downwardly or upwardly is often used topinch a disc mounted to a drive shaft or turntable for rotating. Clampdevices of this type are embodied in U.S. Pat. Nos. 4,722,078,5,146,451, 5,251,192, and 5,253,235. Those are not suitable for use whena plurality of discs need to be in a readily-accessible state at anytime. U.S. Pat. No. 5,375,113 describes a simple clamping mechanism foreach of a number of turntables, which is desirable. However, it remainsto be seen whether the clamping mechanism can provide necessary clampingforce and at the same time can afford an easy release of a loaded disc.Accordingly, there is a need to design a simple, yet effective andspace-saving disc-clamping device with disc-loading and -unloadingflexibility for use in the information processing apparatus inaccordance with the interest of the present invention.

In order to simultaneously launch several software programs directlyfrom either an optical disc or multiple optical discs in accordance withthe interest of the present invention, the hardware of an informationprocessing apparatus must possess multitasking capability. This requiresnot only having a plurality of optical units but also a variety ofsignal process means (such as decoders), control means (including aplurality of microprocessors or a microprocessor with multitaskingcapability) and data transmitting means that all coordinately worktogether for reproducing plural sets of data simultaneously from variousdisc positions on a disc or on several discs and at the same timetransmitting them to a host computer. Otherwise, optical units cannot beinstructed to independently and simultaneously move to a plurality ofpredetermined disc positions, and plural sets of data retrieved fromdiscs cannot be simultaneously processed for returning back to theiroriginal state and then transmitted to a host computer. Thus, pluraldiscs and optical units will make an information processing apparatusmore efficient in terms of access time, but will not necessarily arriveat any multitasking nature needed for future high-speed informationprocessing. One example is exemplified in U.S. Pat. No. 5,375,113 whichdescribes an apparatus that has a plurality of disc storage sites (innonstacking form), each having a separate drive means and an opticaldisc situated together, for reading data specifically from one single,selected optical disc. The main object of the prior art is to eliminatemuch of the costly and duplicative hardware found in systems utilizingdrive cartridges so that common control means such as latches,demultiplexers, and multiplexers are used in order to fulfill its mainobject for delivering a power signal to a selected single disc storagesite for activating its drive means to read information from itsrespective disc. Even though various electronic configurations aregiven, the prior art utilizes only one single microprocessor forinstructing which drive means should be turned on or which servo controldevice should be activated. Under the circumstances, it is not possibleto simultaneously issue multiple commands or control signals to activateand thus to control a plurality of drive means for performinginformation reproduction from plural discs at the same time. In essence,the prior apparatus is specifically designed for informationreproduction to take place one at a time in a selected disc storagesite; thus, it lacks a multitasking capability. This is furthersubstantiatiated in the fact that throughout the entire context, thisprior art neither mentions nor even suggests retrieving informationsimultaneously from plural discs and sending plural sets of retrievedinformation at the same time to its host computer, which are allessential for multitasking to take place.

It is clear that each of the current CD apparatuses has its own meritbut all suffer from various types of disadvantages, such as being unableto launch programs directly from optical discs, lack of multitaskingcapability, the inability for all discs and thus disc positions to be ina readily accessible state with respect to at least one optical unit atany time, lack of disc-loading and -unloading flexibility, lack offlexibility for optical units to travel between discs, lack of anefficient means for an optical read head to selectively travel betweendiscs, too bulky to be installed in a host computer, and/or lack of adevice to safeguard optical discs from being unauthorizedly removed.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide an informationprocessing apparatus with multitasking-capability hardware so that aplurality of optical units are capable of independently andsimultaneously moving to a plurality of disc positions, making itpossible to launch one or several software programs directly from theinformation processing apparatus, to provide true multitaskingcapability, to eliminate tedious and time-consuming softwareinstallation, to offer a kind of copy-right protection, and to alleviatethe burden of a hard-disk drive in information reproduction processing.

Another object of the present invention is to provide an informationprocessing apparatus with turntables having disc-loading and -unloadingflexibility, wherein each turntable comprises a disc-holding and-releasing means with self-clamping and self-releasing feature for eachoptical disc.

Another object of the present invention is to provide an informationprocessing apparatus with turntables and optical units being arranged ina particular manner, wherein each optical unit comprises an efficientdriving means for moving at least one optical read head selectivelybetween discs so that several optical read heads are able toindependently move to a plurality of predetermined disc positions on thesame disc surface of a selected optical disc for simultaneouslyretrieving a plurality of information stored thereon.

Another object of the present invention is to provide an informationprocessing apparatus with turntables and optical units being arranged ina particular manner so that the same driving mechanism is used to movethe optical read head of each of said optical units selectively betweendisc position and between discs, for greatly improving informationaccess efficiency when an optical unit needs to move between discs.

Another object of the present invention is to provide an informationprocessing apparatus with a variety of control means (including aplurality of microprocessors or a microprocessor with multitaskingcapability) so that at least two optical units are able to workcoordinately and simultaneously on separate portions of a softwareprogram, for greatly improving efficiency in information reproduction.

Another object of the present invention is to afford an informationprocessing apparatus with a security means to safeguard the opticaldiscs stored therein from being unauthorizedly removed.

Another object of the present invention is to provide an informationprocessing apparatus with a plurality of disc compartments so that it ispossible to replace an optical disc in one disc compartment while theother optical discs stored in another disc compartment remain operating.

Another object of the present invention is to provide an informationprocessing apparatus with a control means to allow a disc to be scannedeither at a constant angular velocity (CAV) method or at a constantlinear velocity (CLV) method.

Another object of the present invention is to provide an informationprocessing apparatus with at least one turntable that can accommodate anoptical disc with different disc diameters, affording greaterapplication flexibility.

The present invention improves the conventional information reproductionpractice by providing an optical information processing apparatus withmultitasking-capability hardware and disc-loading and -unloadingflexibility means, thereby allowing a user to launch a software programor simultaneously a plurality of software programs directly from anoptical disc or several optical discs stored therein. Themultitasking-capability hardware of the present invention comprises aplurality of turntables, optical units, control means, signal-processmeans, and data transmitting means to coordinately work together formultitaskingly retrieving, controlling and transmitting a plurality ofinformation simultaneously from various position of a disc or severaldiscs to a host computer. Turntables and optical units are arranged andrendered in a particular manner such that at least one optical unit canaccess any positions of at least two discs, a plurality of optical readheads situated in said optical units can independently andsimultaneously access a plurality of positions on the same surface of adisc for high-speed information processing and/or a plurality ofpositions of separate disc surfaces for multitaskingly perform severalprograms at the same time. In accordance with the present invention, thenumber of optical units can be less as compared with that of turntables,for reducing the production costs of making an optical informationprocessing apparatus while maintaining high efficiency in informationreproduction.

An optical information processing apparatus of this type is optionallyequipped with a plurality of disc compartments so that one disccompartment can be independently open for disc exchanging while theother disc compartment remains closed and active programs remainoperating, with a disc holding means having self-clamping andself-releasing feature to facilitate disc-loading and -unloadingoperation, with at least one turntable capable of accommodating a discwith various disc diameters, with a control means to allow a disc to bescanned either at a constant angular velocity (CAV) method or at aconstant linear velocity (CLV) method, and/or a safeguard mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a multitasking information processingapparatus in accordance with the present invention having two opticalunits capable of being used to reproduce information simultaneously fromtwo different positions of an optical disc.

FIG. 2 is a cutaway side view taken along the line 2--2 of FIG. 1,schematically showing an arrangement of the multitasking informationprocessing apparatus.

FIG. 3 is a perspective, partial-cutaway view of a multitaskinginformation processing apparatus of the present invention showing aplurality of multisized discs set in two disc compartments and adisc-compartment transporting means for the front disc compartment to beable to be separately drawn out and into the playhousing.

FIG. 4 is a cutaway view of the underside of the subchassis traversedriving mechanism taken along the line B--B in FIG. 3 of the presentinvention.

FIG. 5 is an exploded perspective view of the disc-compartmenttransporting means seen in FIG. 3 of the present invention.

FIG. 6 is an illustrative top plan view of the multitasking informationprocessing apparatus seen in FIG. 3 with six optical units and eightoptical discs.

FIG. 7 is a block diagram of a control system of the multitaskinginformation processing apparatus shown in FIG. 6 of the presentinvention.

FIG. 8 is an alternative configuration of turntables and optical units.

FIGS. 9A and 9B are perspective top and cutaway side views respectively,for the turntable having a disc-holding and -releasing means withself-clamping and self-releasing feature in accordance with a thepresent invention.

FIG. 10 is a perspective top view of an optical unit as used in FIG. 6that is able to access any position among three disc by horizontallyswinging in accordance with the present invention.

FIG. 11 is a cutaway view of an optical unit with an optical read headand a driving mechanism, and a turntable with a disc-holding and-releasing means in accordance with the present invention.

FIG. 12 is an illustrative, cutaway side view of an optical read head inaccordance with the present invention.

FIG. 13 is an illustrative top view of an optical unit of the presentinvention comprising a driving means in a cutaway top view that enablesan optical read head not only to take a predetermined position on a discbut also to travel between three discs.

FIG. 14 is an illustrative top view of a single optical unit inaccordance with the present invention, having a driving means forallowing at least one optical read head situated therein to travel to atleast one predetermined position selectively between a plurality ofdiscs for retrieving information stored thereon.

FIG. 15 is a cutaway view of an optical unit comprising an upper opticalread head and a lower optical read head for simultaneously reproducinginformation stored on both surfaces of a disc.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 and 2, one embodiment of the present inventionwill be described in detail hereinbelow.

FIG. 1 is a perspective view of an information processing apparatus 1with multitasking capability in accordance with the present invention,having two optical units 43 and 44 and one optical disc 27 in a loadedcondition. Apparatus 1 has a structural frame 1002 on which variousmechanism components are mounted. The frame also serves for theapparatus 1 to be either internally installed as a built-in unit in acomputer or covered by a housing for use as a stand-alone unit to beconnected to a computer. Provided with apparatus 1 is a front panel 3having a disc-releasing button 1004 and a disc supplying slot 5 on whichthere exists a larger opening 6. Disc supplying slot 5 is in a size justallowing an optical disc to be inserted into or extracted out of theapparatus. Larger opening 6 is provided to allow a user's finger to pusha disc, being inserted through first guide roller pairs 7 and 8 and thensecond guide roller pairs 9 and 10 further toward the inside of theapparatus 1, by moving a disc levelling mechanism 11 backward. Disclevelling mechanism 11 has a flat area 12 that is in a horizontalposition slightly lower than the disc-setting table 29 (seen in FIG. 2)of a turntable (or spindle) 13 so that a disc is prevented from beingtipped over and thus is disposed on disc-setting table 29 duringloading. Disc levelling mechanism 11 is slideable along a pair ofhorizontally disposed guide rails 14 through a pair of bearings 15. Whenpushed backward to a predetermined position, disc levelling mechanism 11moves the rear-end portion 16 of a disc clamp arm 17 backward so that adisc clamp head 18 at the distal end of clamp arm 17 is pivoted downwardabout a fulcrum 19 by compressing springs 20 mounted on the rear portionof guide rails 14 so that a rod 21 connecting disc levelling mechanism11 to a mechanical holding mechanism 22 is pulled backward. When pulledto a predetermined position, the top portion of a position holder 23 inmechanical holding mechanism 22 is pivoted backward about a fulcrum 24so as to move the middle portion of position holder 23 over a springstrip 25. The spring strip is arranged to have one end fixed to asupport plate 26 and the other end being free, thus allowing themoveover action of position holder 23 to take place whenever there is anexternal force sufficient to overcome the holding force of spring strip25. Position holder 23 is held by spring strip 25 against the force ofcompressed springs 20, and disc levelling mechanism 11 is thus nottouching the edge of a disc 27.

During disc loading, disc levelling mechanism 11 is moved backward to apredetermined position so that a microswitch (not shown) activates asolenoid 28 to pivot disc clamp head 18 downward further so as totightly grip optical disc 27 onto turntable 13 for subsequent rotation.As detailed in FIG. 2, that is a partial cutaway side view taken alongthe line 2--2 of FIG. 1, on the top of turntable 13 are the disc-settingtable 29 for bearing disc 27 horizontally and a concave portion 30 foraccommodating a convex portion 31 of disc clamp 32. Together withconcave portion 30, convex portion 31 horizontally moves disc 27 to acorrect position for gripping and thus for rotation about turntableshaft 33. The top of convex portion 31 is rotatably connected to discclamp head 18 by a connecting member 34 and is provided with bearings 35for its rotation. While the top portion of turntable 13 is rotatablystabilized by disc clamp head 18 of clamp arm 17, the middle portion ofturntable shaft 33 is rotatably held by bearings 36 mounted on supportframe 37 and the bottom end is supported by a pivot 38. Support frame 37also holds a turntable motor 39. Turntable shaft 33 is rotated byturntable motor 39 through a power transmission system, including a gear40 mounted on a motor shaft 41 and a gear 42 mounted on the near-bottomend of turntable shaft 33.

Apparatus 1 has two optical units 43 and 44 horizontally supported by acommon frame 45 that is held by the top portions of the side panels ofstructural frame 1002. Optical unit 43 has an optical read head 46 witha lens system 47 for reading the information stored on the lower surfaceof disc 27. Read head 46 is supported by a bearing-type carrier member48 which is slideable along a sliding rail 49, and a carrier member 50having a hole with a female screw which is engaged with a screw shaft51. Screw shaft 51 is rotatably supported by bearings 52 and 53 mountedon common frame 45 and has a gear 54 engaged with a gear 55 on motorshaft 56 of motor 57, thus forming a driving mechanism for optical readhead 46. Similarly disposed horizontally on the other end of the samecommon frame 45 is optical unit 44 that comprises an optical read head58 with a lens system 59, support bearings 60 and 61, a bearing-typecarrier member 62, a carrier member 63 with female screw, a gear 64 on ascrew shaft 65, a gear 66 on a motor shaft 67 of a motor 68, thusforming a driving mechanism for optical read head 58. Optical read heads46 and 58 are to the best extent arranged to have travelling pathsfalling onto the same imaginary travelling plane (not shown) parallel tothe disc surface. Upon receiving power signals from microprocessors (notshown), motors 57 and 68 independently and simultaneously move opticalread heads 46 and 58 to predetermined positions in a radial direction ofdisc 27 for simultaneously reproducing information from two separatedisc positions of information-stored area 69 on the same surface of disc27.

In order to perform the abovementioned multitasking, motor 39 and thusdisc 27 are rotated at a constant angular velocity (CAV). Even thoughbeing reduced to half, the storage capacity of a compact disc employingthe CAV method remains enormous, for instance, an 120-mm optical disccan still hold a minimum of 250 megabytes of data. Most importantly, theCAV rotation method allows the apparatus of the present invention torotate at a constant, higher angular velocity for multitaskinglyperforming high-speed information reproduction.

Referring now to FIGS. 3-7, another embodiment of the present inventionwill be described in detail hereinbelow.

FIG. 3 is a perspective, partial-cutaway view of a multitaskinginformation processing apparatus 70 in accordance with the presentinvention, showing a front disc compartment 71 and a rear disccompartment 72 loaded with multisized discs, a pair of disc-compartmenttransporting means 73 for compartments 71 and 72 retractable into andout of a playhousing 74, and various control means on a front panel 75.Note that for simplification of illustration neither thedisc-compartment transporting means on the other side of multitaskinginformation processing apparatus 70 nor optical units are shown in FIG.3. The pair of disc-compartment transporting means 73 not only allowsboth disc compartments to extend out of and retract into playhousing 74but also enables front disc compartment 71 currently containing a single120-mm optical disc to be independently extended to a discloading/unloading position without disturbing the informationreproduction being performed in rear disc compartment 72. As shown inFIG. 3, seven smaller optical discs with 45 mm in diameter arehorizontally spaced in rear disc compartment 72. In the front panel 75of multitasking information processing apparatus 70, there are apush-type button 77 for the open/close operation of front disccompartment 71, a turn-type button 78 for the open/close operation ofboth compartments 71 and 72, a microphone connector 79 for sound outputto an earphone or speakers (not shown), and a volume controller 80 foradjustment of sound level. Also equipped in apparatus 70 is multitaskinginformation processing apparatus 70 is a lockout device 76 for lockingdisc compartments 71 and 72 and thus for safeguarding the optical discsstored therein from being unauthorizedly removed. In addition to amechanical key, the lockout device 76 is responsive to an electricalsignal issued by a host computer, so that it allows the open/closeoperation of disc compartments controlled from the input of the keyboardof a host computer (not shown).

A partial cutaway view of a underside of the subchassis traverse drivingmechanism 81 taken along the line 4-3 of FIG. 3 is shown in FIG. 4. Aservo motor 82 fixed to the subchassis of front disc compartment 71 hasa transverse rubber-roller 83 that tightly contacts the chassis ofplayhousing 74. Upon rotating, transverse rubber-roller 83 thus movesfront disc compartment 71 through disc-compartment transporting means 73to a disc loading/unloading position or a disc playing position. Reardisc compartment 72 is similarly moved by a servo motor 84 with atransverse rubber-roller 85. In order to enable both disc compartmentsto perform simultaneous close/open operation, the rear end of front disccompartment 71 is provided with a protruding part 86 having a centerhole and the front end of rear disc compartment 72 is furnished with aprotruding part 87 having also a center hole. Both center holes arealigned so as to allow the fastening/unfastening operation of latch 88controlled by solenoid 89.

The exploded perspective view of disc-compartment transporting means 73of FIG. 3 is detailed in FIG. 5. Playhousing 74 is made to have narrowopenings 90 and 91 that form supporting rails 92 and 93 respectively.Supporting rails 92 and 93 having bearings 94 and 95 respectivelysupport a suspended sliding device 96 that has five guiding rails. Thetop and the bottom guiding rails 97 and 98 of suspended sliding device96 have bearings 99 and 100 respectively. All together, these rails andbearings allow suspended sliding device 96 to perform sliding operationinbetween supporting rails 92 and 93. On suspended sliding device 96,guiding rail 101 has bearings 102 and 103 and guiding rail 104 hasbearings 105 and 106, while guiding rail 107 has no bearing. Guidingrails 101 and 104 and their respective bearings form a gap accommodatinga sliding rail 108 that is fastened only to front disc compartment 71.At the distal end of sliding rail 108, there exists a sliding roller 109that extends to rear disc compartment 72. Thus, front disc compartment71 can individually slide to a disc loading/unloading position. Fastenedto rear disc compartment 72 is a sliding rail 110 with sliding rollers111 and 112, which slide along the space formed by guiding rails 104 and107. Because of the arrangement of suspended sliding device 96, reardisc compartment 72 can thus be fully opened into a discloading/unloading position.

FIG. 6 is an illustrative top plan view of the multitasking informationprocessing apparatus 70 seen in FIG. 3 with eight optical discs and sixoptical units. Situated in front disc compartment 71 are an 120-mm disc113 horizontally disposed on turntable 134 and two optical units 121 and122 that are able to independently and simultaneously move to anypredetermined disc positions in radial directions with respect to disc113 for multitaskingly reproducing information stored on the lowersurface of disc 113. It is also possible that each optical unit 121 or122 has an additional optical read head as the configuration to be shownin FIG. 15 for simultaneously reproducing information, if any, stored onthe upper surface of optical disc 113.

In addition to the 120-mm disc, turntable 134 disposed within disccompartment 71 can be used to hold a disc with a smaller disc diameter.Turntable 134 is capable of rotating in a CLV or CAV scheme. For aCLV-recorded disc, only optical unit 121 is in operation; while opticalunit 122 will be additionally in effect if the information of disc 113is detected to be in a CAV-recorded scheme. Thus, either CAV-recorded orCLV-recorded discs can be scanned accordingly for informationreproduction, while a CLV-recorded disc doubles its storage capacity, aCAV-recorded disc can be scanned in a high-speed, multitasking way.

Horizontally disposed in rear compartment 72 are seven 45-mm-diameterdiscs 114-120 respectively mounted on turntables 135-141 and fouroptical units 123-126 respectively comprising optical read heads127-132. The disc-setting tables of turntables 136-141 are arranged insuch a manner that discs 114-120 are horizontally aligned with eachother, thus falling onto an imaginary disc plane (not shown). Opticalread heads 129-132 are also aligned to the best extent, forming ahorizontal travelling plane (consisting of the broken circular lines)underneath and parallel to the imaginary disc plane for facilitatingtheir focusing during retrieving the information stored on the lowersurfaces of discs 114-120.

While FIG. 6 shows a configuration in which optical read heads 127-132are all arranged to face the lower surfaces of discs 113-120, it ispossible that some of the optical units 121-126 and thus theirrespective optical read heads 127-132 could be arranged to face theupper surfaces of discs 113-120 so as to provide capability forretrieving information stored on the lower and the upper surfaces ofthese discs.

Turntable 137 and disc 116 are normally rotated in the CAV method by aturntable motor 722 that also drives the other six turntables and thusdiscs to rotate in the CAV method. As illustrated by the broken circularlines, each of optical units 123-126 is able to travel horizontally toan optical disc selected between discs 114-116, between discs 116-118,between discs 116, 119 and 120, and between discs 118 and 119,respectively, for information reproduction. Information stored on the45-mm discs is preferably in the CAV scheme, in order for optical units123-126 to perform high-speed, multitasking information reproduction. Asingle side of a 45-mm disc of this type is capable of holding a minimumof 60 megabytes of data, sufficient for storing a package of executablesoftware programs such as a combination of Microsoft Word® Version 6.0a(about 17 megabytes), Microsoft Excel® Version 5.0 (about 17 megabytes),and Microsoft PowerPoint® Version 4.0 (about 18 megabytes). Use of a45-mm disc or other small-sized discs is also more realistic than thatof an 120-mm disc because software developers such as Microsoft®,WordPerfect®, or Lotus® are most likely to produce their own softwarediscs but each of core software programs is not big enough to even fillup 15% of an 120-mm disc capacity. This also gives a user flexibility tochoose a preferred program, for instance, a word processing programbetween WordPerfect® Version 6.0a (about 28 megabytes) and MicrosoftWord®, since both are unlikely to be stored on the same disc.

As shown in FIG. 6, disc 116 is capable of being simultaneously scannedby three optical units 123-125. This allows three executable softwareprograms, for instance, Microsoft Word®, Excel®, and PowerPoint®, to besimultaneously executed. Disc 118 that can be scanned by optical units124 and 126 is an ideal location for storing a Microsoft Windows® 95disc containing a disk operating system (DOS) and other shared programs.While running executable programs from discs situated in rear disccompartment 72, a user can enjoy digital music by playing a discsituated in front disc compartment 71. The individual open/closeoperation capability of front disc compartment 71 throughdisc-compartment transporting means 73 (shown in FIG. 5) further allowsa user to change a music disc, when needed, without interrupting his/heractive programs that are based on the information reproduction of thediscs situated in rear disc compartment 72.

FIG. 7 is a block diagram of a control system of the multitaskinginformation processing apparatus of FIG. 6. Basically, each of opticalunits 121-126 seen in FIG. 6 comprises a respective one of optical readheads (i.e., pickups) 127-132 and a separate driving means 705. Each ofoptical units 121-126 is interfaced with a separate signal amplifier701, a separate servo system 704, and a separate signal-processingsystem. Each servo system 704 comprises several servo controls thatseparately control a separate driving means 705 for radial tracking of arespective one of optical read heads 127-132 as well as the focusing ofsaid respective one of optical read heads 127-132. Eachsignal-processing system comprises a separate CIRC (Cross InterleavedReed-Solomon Code) decoder 706, a separate CD-ROM decoder 707, and aseparate RAM (random access memory) 708. In essence, each optical readhead is capable of being independently moved by a separate driving meanscontrolled through a separate servo system to a predetermined discposition of an optical disc selected from discs 113-120 and beingindependently focused thereat for retrieving information stored thereon.

Signals sensed by each of optical read heads 127-132 are very weak andthus amplified by their respective signal amplifier 701 to derive usableerror signals and high-frequency signals. The derived error signalsinterface with respective servo system 704 to control focusing andradial tracking of the respective one of optical read heads 127-132.CLV/CAV controls 702 and 703 that also receive the derived error signalsthrough a high-speed system control bus 716 are used to respectivelycontrol the rotation speeds of turntable motors 721 and 722 at aconstant linear velocity (CLV) scheme when either of optical read heads127-132 senses CLV-recorded information from discs 113-120. Thehigh-frequency signals derived from each of optical read heads 127-132are in a compact disc format or specifically in the EFM(eight-to-fourteen modulation) format and thus need to be processed by asignal-process system comprising CIRC (Cross Interleaved Reed-SolomonCode) decoder 706, CD-ROM decoder 707, and RAM (random access memory)708 in order for the signals to be deinterleaved, demodulated, anddecoded for error-correction process, restoring the original sequence ofdata symbols, and finally converting the 14-bit word back to theoriginal 8-bit data symbol. RAMs 708 are used in temporarily storingdata for reassembling during the signal processing proceeded in therespective signal-process system. A digital-to-analog converter (D/A C)710 and audio amplifier 711, which are only necessary when discs haveaudio tracks, are shared by optical units 121-126 for discs 113-120.

In order for multitasking to take place most effectively, disc 116disposed on turntable 137 is normally rotated in the CAV method byturntable motor 722 that also provides the same rotation speed forturntables 135, 136, and 138-141. Optical read heads 129, 130, 131, and132 are able to travel through controlled swinging by respective drivingmeans 705 to positions proximate the lower surface of an optical discselected between discs 114-116, between discs 116-118, between discs116, 119 and 120, and between discs 118 and 119, respectively, forsimultaneously retrieving a plurality of information sets storedthereon. This allows the total number of optical units and thus opticalread heads to be less than that of turntables, thus not only reducingproduction costs but still providing high-efficiency and multitaskingcapability to the information retrieving operation performed on the samedisc and/or different discs.

Also provided in FIG. 7 are (1) a plurality of control means comprisingmicroprocessors (MPUs) 712-714, a ROM/RAM (read only memory and randomaccess memory) 715, and (2) data transmitting means comprising ahigh-speed system control bus 716, ITDM (intelligent time-divisionmultiplexer) 717, wide-band host interface bus 718, and ROM/RAM (readonly memory and random access memory) 719. Each of the buses is acollection of multiple lines forming control bus, address bus, and databus for carrying module-to-module communications. Multitaskingcapability of said control means and said data transmitting means isnecessary in order for a plurality of sets of information to besimultaneously handled and transmitted to a host computer 720. MPUs 712and 713 that share ROM/RAM 715 issue commands or control signals to CIRCdecoders 706 and CD-ROM decoders 707 in a parallel manner throughhigh-speed system control bus 716. The read only memory portion ofROM/RAM 715 contains basic instructions needed for MPUs 712 and 713 toissue a plurality of control signals to a plurality of servo systems 704and a plurality of driving means 705 so as to independently andsimultaneously move optical read heads 127-132 to a plurality ofpredetermined disc positions located either on the lower surface of onedisc or on the lower surfaces of several discs for multitaskinglyreproducing a plurality of information sets constituting either aprogram or several programs stored thereon. The random access memoryportion of ROM/RAM 715 is used for temporarily storing the instructionsissued from host computer 720 served as the input of MPUs 712 and 713for controlling the travelling motions of optical read heads 127-132.

After being deinterleaved, demodulated, and decoded by CIRC decoders 706and CD-ROM decoders 707, the plurality of information sets retrievedfrom optical read heads 127-132 are converted back to the original 8-bitdata symbol. The plurality of converted information sets are multiplexedby ITDM 717 in order to be simultaneously transferred to host computer720 through wide-band host interface bus 718 that is interfaced withmicroprocessor 714, and ROM/RAM 719. Microprocessor 714 withmultitasking capability controls the simultaneous transmitting of themultiplexed information to host computer 720. The read only memoryportion of ROM/RAM 719 contains basic instructions defining how MPUs 712and 713 should work coordinately and simultaneously together to issuecommands to optical units 121-126 in order for a plurality of them toefficiently, multitaskingly, and simultaneously retrieve a plurality ofinformation sets constituting one program or several programs stored onone disc or separately on plural discs. The random access memory portionof ROM/RAM 719 is used as buffer memory storage for temporarily storingthe information to be transmitted when host computer 720 is tied up withother operations. When ready, the host computer 720 can accept theinformation temporarily stored in ROM/RAM 719 in bursts according to theinstruction of MPU 714. While three microprocessors 712-714 are shown inFIG. 7 for controlling the reproducing and transmitting of information,it is possible that more microprocessors can be utilized or thesemicroprocessors are replaced by a single high-performance multitaskingmicroprocessor having a full 32-bit architecture with 32-bit address anddata bus systems or better. Similarly, a less proportion of sharedelectronics such as digital-to-analog converter 710 and audio amplifier711 are possible, as are other electronic configurations.

Owing to the high-speed and multitasking nature of the informationprocessing apparatus 1 of the present invention, it becomes practical toexecute programs directly from optical discs. This eliminates theconventional, tedious and time-consuming software installation procedurein which a software program stored on a plurality of floppy disks or anoptical disc has to be (decompressedly) copied to a hard-disk drive of acomputer from where the software program is then executed. Thisadvantage is described in detail using the exemplary configuration ofFIGS. 6 and 7 in which presumedly disc 116 contains a package ofMicrosoft® software programs including Microsoft Word®, Excel®, andPowerPoint® and disc 118 is a Microsoft Windows® 95 disc containing adisk operating system (DOS) program and other shared Windows files forthe basic operation of host computer 720. After discs 116 and 118 areproperly loaded, optical read heads 129-132 first recognize theexistence of both discs and their corresponding programs in order tocreate a disc directory-structure file, which is similar to a fileallocation table (FAT) created for monitoring the use of the sectors ofa hard-disk drive, for storing the basic information of both discs suchas disc locations and directory structures to the hard-disk drive ofhost computer 720. The disc directory-structure file is updated only ifdiscs 116 and 118 are replaced by other or newer discs are added toother empty turntables. There is essentially no software installation asmanually needed in the conventional practice. Software programs can bewritten in such a way as to automatically create or modify (1) a userdefinable boot file (such as autoexec.bat) on a hard-disk drive in orderto quickly direct the host computer 720 to the locations of the softwareprograms contained in discs 116 and 118, and (2) a working directory onthe hard-disk drive of host computer 720 for storing resulting filesthat will be created or changed during the execution of the programs.

Because none of the program files on the optical disc is copied to thehard-disk drive, the approach of the present invention essentiallyeliminates software installation, therefore alleviating the heavy burdenof a hard-disk drive in information reproduction. Note that according tothe conventional practice both software programs and resulting/workingfiles are mixedly stored on a hard-disk drive for during the routineoperation of a computer. Accordingly, the present invention provides twoadditional advantages: (1) eliminating the need to demand ahigh-capacity hard-disk drive for storing program files that will neverbe altered throughout the entire life of their usage, and (2)eliminating time-consuming hard-disk drive maintenance that involvesfile defragmentation in order for a hard-disk drive to regain itsperformance.

Further, the capability of launching a program directly from an opticaldisc loaded in the information processing apparatus 1 of the presentinvention eliminates the need for an end user to make a set of backupcopies (on floppy disks) for a purchased software program and thus asoftware developer can make its CD-version products not executable froma hard-disk drive, accordingly minimizing illegal-copying of a softwareprogram. This can be simply based on, for instance, the difference inrecording formats between the optical disc and the hard-disk drive. Asoftware developer can embed a key code in the EFM format onto anoptical disc containing the program to be copy-right protected. Withoutdetecting the presence of the embedded key code in the EFM format, acomputer will not execute the program. This in effect disables theprogram to be executed from a hard-disk drive, and thus completelyprevents spreading of a software program. This type of software programcan be considered to be a hardware type in nature, because itscopy-right protection is not relied on the conventional practice ofusing a sealed envelope. As software manufacturers are well protected,consumers can be afforded their opportunity to really try out afully-working version of a software program before deciding whether tokeep it or not.

During the process of booting, host computer 720 in accordance with thebooting instruction of a user defined boot file (e.g., autoexec.bat)created on the hard-disk drive interfaces through wide-band hostinterface bus 718 with MPU 714 that determines and issues the mostefficient instructions to MPUs 712 and 713 in order for them to providepower signals to respective servo systems 704 and respective drivingmeans 705 so as to move optical read heads 130 and 132 to disc 118 forsimultaneously reproducing the disk operating system (DOS) informationand Microsoft Window® 95 information. It is preferred that ROM/RAM 715stores a set of predefined instructions; and, software programs storedon the disc are written and arranged in a particular manner so thatoptical read head 130 is controlled to move specifically to apredetermined position selected from a set of disc tracks that containsound information and/or other non-video files while optical read head132 is instructed to move specifically to another predetermined positionselected from another set of disc tracks that contain video informationand/or other non-sound files. In other words, optical read head 130 iscontrolled for producing sound effects and other non-video files whileoptical read head 132 is instructed mainly to produce video images andother non-sound files. Controlled by data transmitting signals issued bymicroprocessor 714, video images can be transmitted in bursts throughwideband host interface bus 718 directly to a video circuit (not shown)of host computer 720. With this scheme, reproduction of video images andsound effects can be simultaneous, thus allowing a program to beexecuted at a much higher speed and arriving at a ready-to-run state inno time.

In contrast, in accordance with conventional practice, the proceeding ofa Windows-based software program is inevitably interrupted constantly,especially when video information and sound information are too large tobe read within a reasonable time period.

Disc 116 loaded on turntable 137 can be simultaneously accessed by threeoptical read heads 129-131. Accordingly, an information processingapparatus of this type will hardwarely allow a user to simultaneouslyexecute three different programs at the same time. Front disccompartment 71 seen in FIG. 6 has its own turntable 134, optical units121 and 122, CLV/CAV control 702 and turntable motor 721 (both shown inFIG. 7) for rotating and scanning an 120-mm CD at either the CLV or theCAV method; thus, an audio CD can be simultaneously played while a useris executing the software programs stored on the discs disposed in reardisc compartment 72.

Shown in FIG. 8 is an information processing apparatus 800 with analternative configuration of disc-storage locations and optical units,having a rear disc compartment 801 different from FIG. 6. The rear disccompartment 801 of FIG. 8 bears six discs 802-807 and six optical units808-813. In accordance with this embodiment, at least, discs 802 and803, discs 804 and 805, and discs 806 and 807 are respectively alignedwith each other. Further, each of optical units 808-813 is capable oflinearly moving along a screw shaft 814 and a sliding rail 815 by apredetermined distance in a radial direction of a selected disc so as toallow each of respective optical read heads 816-821 to becorrespondingly positioned on a predetermined disc position forretrieving information stored thereon. Thus, each of discs 802-807 canbe scanned either by one optical read head or by two optical read headssimultaneously for information reproduction.

FIGS. 9A and 9B are perspective top and cutaway side (along the line9B--9B) views respectively of the turntable showing a disc-setting tableand a disc-holding and -releasing means having a self-clamping and-releasing mechanism for detachably holding an optical disc thereon inaccordance with the present invention. The disc-holding and -releasingmeans and thus the self-clamping and -releasing mechanism of theturntable herein are characterized by miniaturization and are designedto facilitate disc loading/unloading operation. In the following,exemplary illustration is given to turntable 135 and disc 114 disposedthereon as seen in FIG. 6. To facilitate illustration, only FIG. 9B isloaded with disc 114. Turntable 135 basically comprises a disc-settingtable 150 for horizontally bearing a disc thereon and an elevated centerportion 151 which is sized to fit into the center hole of optical disc114 as shown in FIG. 9B. Elevated center portion 151 comprises a hollowmember 152 being in a cylindrical shape wherein a spring device having aflat bottom 153 and four strip ends 154 is situated on the top of spring155 that provides up-and-down motion through a guiding ring 156. Duringdisc loading, spring strip ends 154 are forced to retract through fouropenings 157 to the inside of hollow member 152 and then returns totheir outward-biased normal position that also provides a slightlydownward force so as to hold disc 114 in place as shown in FIG. 9B. Alsoin the elevated center portion 151 is a release mechanism having apressing button portion 158 and a release bottom portion 159. Pressingbutton portion 158 is confined in the inside of hollow member 152 bymeans of the circular edge 160 of hollow member 152. When pressingbutton portion 158 is pushed by a user's finger for disc unloading,release bottom portion 159 and thus flat bottom 153 are accordinglymoved downward to cause the retraction of spring strip ends 154 into theinside of hollow member 152, thus releasing disc 114. To obtainself-releasing function, disc-setting table 150 is made to comprisedisc-releasing springs having one end held by the rectangular slots 161and the other end 162 biased upward but capable of being pushed downwardwhen disc 114 is held in place by spring strip ends 154.

Hollow member 152 may optionally have a noncircular outer boundary suchas having a locking portion 163 for adapting an optical disc having acenter hole with a complementary boundary or shape so as to ensureprecision griping, thus allowing disc 114 to rotate at a speed muchhigher than the conventional practice.

FIG. 10 is an enlarged perspective top view of optical unit 124 andthree adjacent discs 116-118 which are arranged in the sameconfiguration as seen in FIG. 6, illustrating that a single drivingmeans (or swing mechanism) is used to horizontally move an optical readhead selectively between various disc positions as well as between aplurality of discs for information reproduction in accordance with thepresent invention. Information starting from disc directory structuresis stored from each innermost track 164 to the outermost edge of discs116-118. Located at the distal end of optical unit 124 is an opticalread head 130 that is currently positioned at the innermost track 164 ofdisc 118. Optical read head 130 is able to swing about axis 166 that isrotatably supported by bearing 191 and supporting frame 222 attached todriving means 168, in accordance with a broken circular line ortravelling path 167. The swing motion of optical read head 130 ispowered by the driving means (or swing mechanism) 168 through a toothedbelt 169. Discs 116-118 are horizontally aligned with each other so asto facilitate the focusing action of optical read head 130 to each ofthe discs, and are concentric with respect to axis 166 so that theinnermost tracks of the three discs are reachable as indicated by thebroken circular line 167. Thus, by spinning these discs and by swingingoptical read head 130 about axis 166, information stored on any tracksof discs 116-118 becomes readily reproducible.

FIG. 11 is a cutaway view, showing turntable 139 on which disc 118 ishorizontally disposed and optical unit 124 that comprises optical readhead 130 and driving means (or swing mechanism) 168 for providing anecessary force to horizontally swing optical read head 130 to apreselected position. Turntable 139 has a turntable shaft 213 which isrotatably supported by bearings 214 and 215 that are attached a tosupporting frame 216 fastened to the bottom frame 224 of compartment 72.At the bottom portion of turntable shaft 213 are pulleys 217 and 218that are connected respectively by toothed belts 219 and 220 fortransmitting rotation power from turntable motor 722 seen in FIG. 7 andto other turntables. Under these circumstances, a plurality ofturntables can be driven by a single turntable motor. This greatlyreduces construction costs and space for commercializing the opticalinformation processing apparatus of the present invention.

Optical read head 130 situated in an optical-read-head housing 221comprises a semiconductor laser diode 170, a lens system 171,photosensors 172 and 173, and a focusing mechanism 174 situated on thedistal end of optical-read-head housing 221. As detailed in FIG. 12,semiconductor laser diode 170 is a light source for producing a laserbeam. The laser beam emitted from laser diode 170 is converted by acollimator 175 to a parallel light beam 176 that is bent at an angle of90° by means of a mirror 177 and is then focused by the focusingmechanism 174 onto the information-stored surface layer 178 of disc 118.A beam of light reflected from the information-stored surface layer 178is deflected at an angle of 90° C. by mirror 177 and is then condensedthrough a quarter-wavelength (λ/4) plate 179, polarizing beam-splittingprisms 180 and 181, and the lens 182 to the photosensor 172 that readsthe change of the output signals.

Focusing mechanism 174 detailed in FIG. 12 comprises an objective lens184 attached to a vertically movable device 185, tension springs 187,and a focus-tracking coil 188 wound around a stationary bobbin 189.Vertically movable device 185 has a ring-type magnet 186 fixedlysituated therein. Tension springs 187 provide tension and keep objectivelens 184 straight in the focusing mechanism 174 as objective lens 184vertically moves. Projection lens 183 and photosensor 171 are arrangedin a direction of the beam that is reflected from disc 118, bent bymirror 177, and condensed through λ/4 wave plate 179, polarizingbeam-splitting prisms 180 and 181, thereby detecting a focusing error.In the focused condition, a zero error exists from photosensor 171. Whenan error signal produced from either a too-far or a too-close conditionis detected by photosensor 171, the detected error signal is amplifiedand fed to focus-tracking coil 188 wound around stationary bobbin 189which then produces a magnetic field to cause ring-type magnet 186 andthus objective lens 184 to move in the relevant direction until theerror signal becomes zero and the beam is in focus.

As shown in FIG. 11, the other distal end of optical-read-head housing221 is attached to a shaft 190 that is rotatably supported by bearings191 and 192 and has a pivoted end 193 for its swinging. Bearings 191 and192 are respectively supported by top and bottom supporting frames 222and 223 fixedly attached to driving means 168. A stop pin 194 fixedlyattached to the bottom frame 224 of rear disc compartment 72 and twohelical tension springs 195 and 196 arranged in opposite direction areprovided in order to produce torque restrain for a steady swing of shaft190 about its axis 166. A stop pin 197 fixedly attached to the bottomportion of shaft 190 is provided for shaft 190 to rest at a referenceposition. Toothed belt 169 connects a pulley 198 on shaft 190 and apulley 199 on moving-coil shaft 200 for transmitting rotation power.Pulley 199 has a diameter larger than pulley 198 so that driving means168 can provide a maximal swing angle of 300 degrees. Supported bybearings 201, moving-coil shaft 200 has top and bottom pivots 202 and203 that are respectively held in place by top and bottom frames 204 and205 for its swing.

Driving means (or swing mechanism) 168 as seen in FIG. 11 is furtherdetailed in FIG. 13 in a partial cutaway top view in which top frame 204and supporting frame 222 (seen in FIG. 11) are removed. In accordancewith the present invention, driving means 168 is able to provide arotating force to horizontally swing optical read head 130 about axis166 for a maximal swing angle of 300° as indicated by the brokencircular line or travelling path 167. This allows optical read head 130to travel between various positions of a selected disc as well asbetween discs 116-118. Most importantly, the travelling of optical readhead 130 between these discs is as rapid as that between variouspositions within the selected disc, because the travelling involvesneither multidirectional nor three-dimension maneuver but needs only onesingle-directional movement.

In order to provide a rotating force, driving means 168 is arranged asshown in FIGS. 11 and 13, in which one end of a moving coil 206 isfixedly attached to moving-coil shaft 200, the other end is allowed tofreely travel in a uniform air gap 207 defined by an outer soft-ironpole piece 208 and inner pole piece 209. Bonded to outer soft-iron polepiece 208 is a magnet 210. An air gap 211 extending to the inner area ofcovering frame 212 is provided in order for moving-coil shaft 200 withattached moving coil 206 to be assembled into the configuration of FIG.13 and also allows moving-coil shaft 200 and the fixedly attached end ofmoving coil 206 to rotate about the axis defined by pivots 202 and 203(FIG. 11). Attached to the outer circular area of magnet 210 is alaminated steel shell 213 that acts as a magnetic collector ring andalso effectively shields the element from stray fields.

Illustrated in FIG. 14 is another preferred embodiment of the presentinvention, wherein information processing compartment 300 has an opticalunit 301 comprising an optical read head 302 and a driving means (orswing mechanism) 303, wherein said driving means 303 enables saidoptical read head 302 to travel by swinging about axis 316 to anypositions on discs 304-309 respectively mounted on turntables 310-315for information reproduction. Each of these discs has a diameter of 45mm. Within the compartment, these discs are horizontally andconcentrically disposed at predetermined positions such that the disccenters are at an equal distance from the axis 316 of optical unit 301.Underneath turntable 310 is a turntable motor (not shown) which is alsoused to drive turntables 231-315 simultaneously. Each of turntables310-315 comprises its own disc-loading and releasing means withself-clamping and -releasing feature so that once being loaded ontoturntables 310-315, discs 304-309 will remain being clamped at any timeand can be rotated simultaneously. Thus, without going through otherintermediate loading stages (such as internal disc changing or selectingused in the prior art), information reproduction can be effectivelyperformed by simply moving optical read head 302 to a disc selectedbetween discs 304-309 disposed within the same compartment. Thiseliminates any need to equip an information processing apparatus with adisc-turntable rotating mechanism, a disc transporting means, or otherdisc changers described in prior arts such as U.S. Pat. Nos. 5,119,354,5,146,451, 5,193,079, and 5,334,218.

Driving means 303 enables optical unit 301 to perform a maximum of 350°swing about axis 316, starting from position 318, for accessingselectively between disc tracks and discs 304-309. In essence, opticalread head 302 of optical unit 301 travels in accordance with the brokencircular line 317; thus, any information stored on these discs becomesreadily accessible. Because of being designed for discs with smallersizes and being equipped with a single turntable motor and a sharedoptical unit 301, compartment 300 can be economically produced in a sizesimilar to the commercially available single 120-mm-disc player, forbeing installed into the interior of a personal computer.

Apparatus 300 is optionally equipped with a servo control (not shown),which enables the turntable motor to rotate at a constant linearvelocity (CLV) in addition to at a constant angular velocity (CAV). Useof the CLV-recording method doubles the storage capacity of the 45-mmdisc to 120 megabytes from 60 megabytes compared with use of theCAV-recording method. This is advantageous for a software developer tofit a lengthy program or several programs as a package into a singlesmall-sized disc. On the other hand, if information to be stored in a45-mm disc is less than 60 megabytes, the CAV method is preferred inorder to allow information reproduction to be performed at a higherspeed.

In a further preferred embodiment of the present invention, discs304-309 shown in FIG. 14 are arranged in a manner so that there is anopen space between disc 304 and disc 309 for optical unit 301 to park atposition 318. This open space allows optical unit 301 of apparatus 300to further comprise an upper optical read head 320 in addition to loweroptical read head 321 as shown in FIG. 15, without causing anyinconvenience to disc loading/unloading operation. Upper and loweroptical read heads 320 and 321 have configurations similar to theembodiments of optical read head 130 singularly situated inoptical-read-head housing 221 hereinbefore detailed in FIG. 12.Optical-read-head housing 322 has a horizontal open slot 325 for anoptical disc selected from discs 304-309 to insert therein so that theinnermost tracks on both surfaces of the disc become simultaneouslyaccessible to an objective lens 323 of upper optical read head 320 andto an objective lens 324 of lower optical read head 321. Note thatobjective lens 323 is disposed in a direction facing to objective lens324, so as to face the other surface (i.e., the upper surface) of anoptical disc selected from disc 304-309. The use of two optical readheads in an optical unit provides twofold advantages: doubling not onlythe information storage capacity of a disc but also the speed ofinformation reproducing.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be understood that such embodiments areprovided by way of example only. Numerous variations, changes,modification, and substitutions will occur to those skilled in the artwithout departing from the invention herein. Accordingly, it is intendedthat the invention be limited only by the spirit and scope of theappended claims.

What is claimed is:
 1. An information processing apparatus withmultitasking function, the information processing apparatuscomprising:(a) a plurality of turntables, each comprising a disc-settingtable for mounting an optical disc; (b) a plurality of optical units,each comprising a driving means and an optical read head, wherein saiddriving means is provided for moving said optical read head in a radialdirection of said optical disc to a predetermined disc position on asurface of said optical disc; (c) means for simultaneously controlling aplurality of said driving means to move a plurality of said optical readheads to a plurality of predetermined disc positions on at least twooptical discs for retrieving information stored thereon; (d) a pluralityof signal-process systems for converting a plurality of information setsretrieved by said plurality of optical read heads from a compact discformat to the original state of the information; and (e) datatransmitting means for transmitting a plurality of the information setsconverted by said plurality of signal-process systems to a hostcomputer.
 2. The information processing apparatus of claim 1, wherein atleast one of said optical units further comprises an additional opticalread head having an objective lens disposed in a direction facing theother surface of a selected optical disc so that information stored onboth surfaces of said selected optical disc can be simultaneouslyaccessed.
 3. The information processing apparatus of claim 1, whereinsaid plurality of turntables and said plurality of optical units arearranged in such a manner that at least two optical discs adjacentlystored in said information processing apparatus are generally alignedwith each other so that said at least two optical discs are selectivelyaccessible by at least one of said optical read heads.
 4. Theinformation processing apparatus of claim 1, wherein a selectedplurality of said optical read heads are generally aligned with eachother so that at least two of said selected plurality of optical readheads are capable of being independently moved by separate driving meansto at least two of predetermined disc positions on the same surface of aselected optical disc for simultaneously retrieving at least two sets ofinformation stored thereon.
 5. The information processing apparatus ofclaim 1, wherein;said plurality of turntables are horizontally arrangedin such a manner that a selected plurality of optical discs storedthereon are generally fallen onto an imaginary horizontal disc plane;and said plurality of optical units are arranged in such a manner thatthe traveling paths of a selected plurality of said optical read headsare generally fallen onto two imaginary horizontal travelling planes,one above and the other below said imaginary horizontal disc plane; sothat said selected plurality of optical read heads are able toindependently move to a selected plurality of predetermined disc trackson both surfaces of at least one of said selected plurality of opticaldiscs for simultaneously retrieving a plurality of information setsstored thereon.
 6. The information processing apparatus of claim 1further comprising at least one disc compartment for storing saidplurality of turntables and said plurality of optical units therein, anda security means for locking said at least one disc compartment frombeing unauthorizedly opened so as to safeguard optical discs storedtherein.
 7. The information processing apparatus of claim 6, whereinsaid security means is selectively controllable by a mechanical meansand by an electrical signal.
 8. The information processing apparatus ofclaim 1 further comprising two disc compartments for storing saidplurality of turntables, and a disc-compartment transporting means thatenables one of said two disc compartments to independently extend outand retract into said information processing apparatus for discexchanging while the other of said two disc compartments remains in aretracted position.
 9. The information processing apparatus of claim 1further comprising a turntable motor and a control means, wherein saidcontrol means is provided for controlling the rotating of said turntablemotor selectively at a constant angular velocity and at a constantlinear velocity.
 10. The information processing apparatus of claim 1,wherein at least two of said optical read heads are moved by respectivedriving means for coordinately proceeding the reproduction of a softwareprogram, one of said at least two optical read heads is moved to a setof disc tracks consisting of the data that are not responsive toreproducing the sound effects of said software program, and another oneof said at least two optical read heads is moved to another set of disctracks consisting of the data that are not responsive to reproducing thevideo images of said software program, so that said sound effects andsaid video images of said software program are simultaneouslyreproduced.
 11. The information processing apparatus of claim 1, whereineach of said turntables comprising:(a) a disc-setting table for bearingan optical disc thereon, said disc-setting table comprisingdisc-releasing means having an outward-biased tendency for pushing saidoptical disc apart from said disc-setting table; and (b) a disc-holdingand -releasing means comprising (i) a hollow member that has an elevatedcenter portion being sized to fit into the center hole of said opticaldisc, (ii) disc-holding means retractable into the inside of said hollowmember but preferably returning to its outward-biased normal positionprotruding to the outside of said hollow member for locking said opticaldisc in place, and (iii) a releasing button that upon pressing retractssaid disc-holding means to the inside of said hollow member, so as toallow said disc-releasing means to push said optical disc apart fromsaid disc-setting table.
 12. The turntable of claim 11, wherein theelevated center portion of said hollow member has a noncircular outerboundary for adapting a disc having a center hole with a complementaryboundary so as to ensure precision griping, thus allowing said disc torotate at a high speed.
 13. An information processing apparatuscomprising:(a) a disc compartment; (b) a plurality of turntablesdisposed within said disc compartment, each of said turntablescomprising a disc-setting table for mounting an optical disc thereon;(c) an optical unit comprising a driving means and at least one opticalread head, said driving means being provided for moving said at leastone optical read head in a radial direction relative to at least one ofsaid disc-setting tables; (d) means for controlling said driving meansto move said at least one optical read head for selectively accessingoptical discs mounted on at least two of said plurality of turntables;and (e) at least one signal-process system for converting theinformation retrieved by said at least one optical read head from acompact disc format to the original state of the information;whereinsaid turntables, said disc-setting tables, and said optical unit arearranged in such a manner that optical discs mounted on saiddisc-setting tables are generally aligned with each other so as to allowsaid optical unit to selectively access each of said optical discs. 14.The information processing apparatus of claim 13, wherein said opticalunit comprises two optical read heads having respective objective lensesfacing to each other so that said two optical read heads are capable ofbeing moved simultaneously by said driving means for retrievinginformation stored on both surfaces of a selected optical disc thereon.15. The information processing apparatus of claim 13 further comprisinga turntable motor and a control means, wherein said control means isprovided for controlling the rotating of said turntable motorselectively at a constant angular velocity and at a constant linearvelocity.